Study On The Removal Of Arsenic,Lead,Cadmium,Mercury From Several Traditional Chinese Medicines By Inorganic Type Lon Exchange Resins

Expulsion of the heavy metal reside exceeding the legal limit from Traditional Chinese Medicine(TCM) can not only lead to solve the problem of safe medication, but also can help us to break away from the dilemma that TCM cannot go abroad. Our group of the engineering center for inorganic ion exchange resin collaborate with the team from Luoyang Dingli Environmental Protection Technology co. Ltd. to develop a series of inorganic ion exchange resin, named SI series. These series of ion exchange resins have been primitively used in hydrometallurgy and in removing the heavy metal ions in sewage; the better test results have been obtained. Some of them have been achieved semi-industrial stage. Inspired by these two preliminarily successful application in these two areas, we design to use this type of ion exchange resin to clear away the superfluous heavy metal residue in TCM, such as lead, cadmium, mercury, arsenic.We randomly purchase six kinds of TCM from the drug story, such as Quick stop cough syrup, Compound earthworm capsule, Salvia miltiorrhiza injection, Ginseng fruit of Chinese magnoliavine particles, Bezoar detoxify piece, Compound salvia tablet. The six kinds of TCM is pretreated by the wet digestion of HNO3- HClO4(4:1) at atmospheric pressure, then determined are the residual content of Pb, Cd, As and Hg in the six kinds of TCM by inductively coupled plasma emission spectrometer(ICP). Test results show that, according to the standard by American FDA, excessive heavy metal ions in the six kinds of TCM come true; among them, all of the four heavy metals in Compound salvia tablet and Ginseng fruit of Chinese magnoliavine particles exceed the legal limit; the amount of Pb, Cd and As in Salvia miltiorrhiza injection and Compound earthworm capsule are all excess; Bezoar detoxify piece contain too many Hg and As; There are excess Pb and As remaining in Quick Stop Cough Syrup.We selected Bezoar detoxify piece and Compound salvia tablet to determine their own active ingredient, such as baicalin and Dan phenolic acid B through HPLC. The test results display that the contents of the two active ingredients fit well to “Chinese Pharmacopoeia 2010”。Because the four kinds of heavy metal residue in compound salvia miltiorrhiza are all exceed the legal limit, we select different type of inorganic ion exchange resins(for example: SI-2、SIB、SIB-46、SIB-53、WBAS-1 and WA-3, et al) to separate this excessive heavy metal from it. The test results show that when SIB-46、SIB-53 and WBAS-1 are used to delete the excessive heavy metal, the removal efficiency of As goes on to be better, the removal rate is more than 85%; while the Pb removing rate is more than 55%, the Cd clearance reaches only 8%-40%; the removal of Hg obtains the best result, Hg could not be determined when the TCM was ion exchanged. But after treated by this three ion exchange resins, the active ingredient(Dan phenolic acid B) can not be determined through HPLC. For this reason, this three kinds of ion exchange resins are foreign to removal of heavy metal from this drug.When the dosage of SI-2 ion exchange resin is 20 times than that of the drug, the other selected conditions are as follows: pH 7, 85% ethanol as elution agent(3 times of usage is equal to the dosage of resin), velocity is 5 ml/min, the sample temperature controlled at 25℃ before added into the column, respectively. Under the condition, the sample is columned. After ion exchanged, Compound salvia tablet has not been found the lead, cadmium, mercury, and arsenic; and the recovery rate of Dan phenolacid B reaches 90%. While the usage amount of WB-3 is 20 times than the amount of the drug, pH 5, 85% ethanol used as elution agent, the dosage of the eluent agent is equal the 9 times of resins and the velocity is changed to 7 ml/min, the temperature controlled to 25 ℃ before added into the column. Under the conditions, after the sample is passed through the column to ion exchange, the heavy metal residue in compound salvia miltiorrhiza disappears, the recovery rate of Dan phenolacid B equally match with 78.20%。If the resins is replaced by SIB, and when the conditions selected are as follow: its dosage is 20 times than that of the drug, pH 5, 75% ethanol as elution agent(3 times of usage equals the dosage of resin), current speed is 5 ml/min, the sample temperature controlled at 25℃ before added into the column, the sample is passed through the column. After that, all of the four excessive heavy metal are removed from the drug, and the recovery rate is equal to 50.98%。The legal limit on heavy metal residue in TCM regulated by our country have a big gap with the limited standards approved by US FDA. Because China has joined the WTO, we should strictly produce TCM in conformity with the international generic production standards. But according to the rules by FDA, the lead, cadmium, mercury, and arsenic residue in most of TCM simultaneously exceed the legal standard. From this point of view, SI-2 is the best propitious to removing the excessive heavy metal ions(lead, cadmium, mercury, arsenic) from TCMs among the three kinds of SI- 2, SIB, WB-3 ion exchange resins.